ARP 203-5001 Pro Series 2-Bolt Main Bolt Kit Toyota 4AGE 1.6L DOHC Corolla MR2

Vehicle Fitment

• 1984-1987 Toyota Corolla AE86 (4AGE 1.6L DOHC 16V I4, RWD/FWD)
• 1988-1992 Toyota Corolla AE92 (4AGE 1.6L DOHC 16V I4, FWD)
• 1985-1989 Toyota MR2 AW11 (4AGE 1.6L DOHC 16V I4, RWD)
• 1988 Toyota MR2 AW11 Supercharged (4AGZE 1.6L Supercharged I4, RWD)
• Compatible with any engine build or swap using the Toyota 4AGE 16V or 20V block with a 2-bolt main cap configuration

Fitment Notes

• Designed for 2-bolt main cap configuration - confirm your 4AGE block uses 2-bolt mains before ordering
• Compatible with both 16V (redtop/bluktop) and 20V (silvertop/blacktop) 4AGE variants sharing the same main cap bolt pattern
• Use ARP Ultra-Torque assembly lubricant on bolt threads and under head for accurate torque readings - do not use engine oil
• This is a bolt kit - not a stud kit; bolts thread directly into the block without a separate nut

Features

• Made from 8740 chromoly steel, rated at 190,000 psi tensile strength - significantly stronger than OEM main cap hardware
• Threads rolled after heat treatment for up to 2,000% better fatigue strength compared to bolts threaded before heat treating
• Reduced wrenching head with large underhead radius for improved load distribution and reduced stress concentration
• Eliminates main cap walk and fretting - critical in high-RPM 4AGE builds running aggressive camshafts or forced induction
• Hardened parallel-ground washers included for uniform clamping force and accurate torque readings
• Reusable fasteners - do not stretch or deform under rated load unlike OEM hardware

Specifications

• Part Number: 203-5001
• Material: 8740 Chromoly Steel
• Tensile Strength: 190,000 psi
• Main Bolt Style: 2-Bolt (Bolt, not Stud)
• Head Style: Reduced Wrenching
• Finish: Black Oxide
• Washers Included: Yes (Hardened Parallel-Ground)
• Quantity: Complete kit for one engine

Included Components

• 1x Complete set of ARP 8740 Chromoly Main Cap Bolts (2-bolt main)
• 1x Set of Hardened Parallel-Ground Washers
• 1x ARP Ultra-Torque Fastener Assembly Lubricant

Product Description

The ARP 203-5001 is a Pro Series main bolt kit designed for the Toyota 4AGE 1.6L DOHC engine, covering the AE86 Corolla, AE92 Corolla, and AW11 MR2 - including the 4AGZE supercharged variant. The 4AGE is a high-revving, lightweight engine widely used in motorsport and performance builds, and any serious engine build should address the main cap bolts as part of the bottom end assembly. OEM main cap hardware is not designed for repeated high-RPM loading, and replacing it with these ARP bolts eliminates the risk of main cap walk and thread damage in the block.

Rated at 190,000 psi and manufactured from 8740 chromoly with threads rolled after heat treatment, these bolts provide 2,000% better thread fatigue life than conventionally manufactured main bolts. Hardened washers are included for consistent load distribution. Compatible with both 16V and 20V 4AGE blocks sharing the 2-bolt main cap pattern - covers a complete engine in one kit.